Stethoscope with improved eotatable binaural couplings



Nov. 29, 1966 I D. R. ALL'EN 3,

STETHOSGOPE WITH IMPROVED ROTATABLE BINAURAL COUPLINGS Filed Oct. 20, 1965 INVENTOR. DEREK A. ALLEN ATTORNEY United States Patent 3,288,246 STETHOSCOPE WITH IMPROVED ROTATABLE BINAURAL COUPLINGS Derek R. Allen, Montrose, Calif., assignor to Allen Medical Instrument Corporation, a corporation of California Filed Oct. 20, 1965, Ser. No. 498,834 3 Claims. (Cl. 181-24) This application is a continuation-in-part of my application Ser. No. 248,494, filed Dec. 31, 1962, now Pat. No. 3,223,195, for Stethoscope With Convertible Receiver.

This invention relates to stethoscopes and has as its object to provide an improved adjustable binaural coupling mechanism, wherein:

(1) Provision is made for rotation of the binaurals on their longitudinal axes for adjustment to a physicians ears;

(2) Such rotatable adjustment means is combined with means for lightly spring-loading the binaurals against the wearers ears;

(3) The binaurals are rotatably mounted in spring sleeves formed integrally on the ends of spring arms which provide the aforesaid spring-loading;

(4) The spring sleeves have yielding frictional engagement with the binaurals to yieldingly hold them in selected positions of rotative adjustment; and

(5) The spring sleeves are yieldable to permit rorative adjustment of each binaural with substantial equal facility in both directions about its axis.

Other objects and advantages will become apparent in the ensuing specification and appended drawing in which:

FIG. 1 is a plan view of a stethoscope embodying the improvements of my invention;

FIG. 2 is an end view of the binaural spring yoke;

FIG. 3 is a plan view of the yoke;

FIG. 4 is a side view of the stethoscope;

FIG. 5 is a fragmentary axial sectional view of the binaural coupling, taken on the line 55 of FIG. 4; and

FIG. 6 is a detail cross-sectional view of the same taken on line 66 of FIG. 5.

Referring now to the drawings in detail, and in particular to FIG. 1, there is shown therein, as an example of one form in which the invention may be embodied, a stethoscope comprising, in general, a receiver A, a binaural unit B, and a flexible transmission tube C, one end coupled to receiver A.

Binaural B comprises a T-fitting 55 coupled to the other end of transmission tube C, a pair of flexible branch tubes 56 coupled to the respective sides of fitting 55; a pair of binaurals 57, of metal or stiff plastic tubing, each having one end inserted into a corresponding end of a respective branch tube 56 and each having a conventional ear plug 58 at its other end; and the improved spring yoke 59, comprising a yoke portion of spring metal in ribbon form and a pair of spring clamp sleeves 60, integral with its respective ends. Clamp sleeves 60 encircle the respective binaurals 57 and are in yielding constrictive frictional engagement therewith so as to permit the tubes to be rotated and to hold them in positions of rotational adjustment. The flexibility of branch tubes 56 is such that they can rotate with the ends of binaurals 57 to which they are attached, torsionally adjusting themselves'to the rotational adjustment. The yoke 59 is contoured to provide the proper forked configuration of the pair of tubes 56, and provides support and protection for these tubes. The clamp sleeves 60 are joined to the respective ends of the arms of yoke 59 by integral webs 61 which are bent at right angles to the respective arms and project in opposite directions in a common plane adjacent to the plane of the edges of the yoke arms at one side of the yoke. The sleeves 60 are rolled so as to position them generally in the general plane of the yoke 59 (FIG. 2).

Sleeves 60 are of suflicient stiffness and area so as to provide for rotational adjustment of each binaural in both directions of rotation about its longitudinal axis, without substantial variation of its yielding grip on the binaural stern, i.e., without any substantial snubbing action when the stem is rotated so as to tend to draw the free end of its sleeve 60 toward the adjacent web 61, and without any substantial relaxation of its grip when the stem is rotated in the opposite direction. The stiffness of the sleeve and its area of bearing engagement with the binaural stem (the axial length of the sleeve being at least equal to its diameter) are sufli-cient to provide satisfactorily appreciable resistance to rotation of the binaurals in the directions tending to drag the free ends of the loops away from the adjacent webs 61, thereby facilitating such adjustment.

The frictional grip on the binaurals also serves to inhibit any tendency of the spring yoke 59 to slide axially along the binaural stems. Thus the yoke is maintained in the position shown in FIG. 1, with the central web portion of the yoke 59 in engagement with the T-fitting 55, and with the ends of branch tubes 56 substantially abutting the sleeves 60.

The yoke 59 provides a gentle spring-loading of the ear plugs 58 toward one another for sung seating in the ear canals. The clamp sleeves 60 provide a gentle grasp of the binaurals 57, sufficient t0 normally hold them in positions of rotational adjustment yet yielding readily to such rotational adjustment for fitting the binaurals to the ears of the doctor who is to use the stethoscope.

The transmission tube C and branch tubes 56 utilize a plastic tubing with smooth shiny walls which, in the interior of the tubing, insure maximum sound transfer to the ears. The tubing is quite flexible so as to readily twist in response to rotational adjustment of the binaurals.

I claim:

1. A stethoscope comprising a communication tube having a pair of flexible branch tubes branching from one end thereof; a pair of binaurals of rigid tubing having respective ends coupled to respective ends of said branch tubes; and a yoke of spring sheet material having respective arms of substantially flat ribbon form disposed in planes at right angles to a common plane of said yoke, having their one ends joined by a transverse connecting bridge and having, at their other ends, integral extensions of dihedral angular form comprising respective end portions of said arms and respective webs joined to said end portions by right-angle bends and extending in opposite directions in a plane adjacent and parallel to the comm-on plane of the side edges of said arms at one side of said yoke, and respective curled sleeves formed as continuations of said webs, tangent to said webs, extending continuously therefrom substantially entirely around said binaurals, and centered in the general plane of the yoke, said sleeves encircling respective binaurals immediately adjacent the ends of said branch tubes with a yielding frictional engagement such as to permit rotational adjustment of said binaurals and to hold them in selected positions of such rotation-a1 adjustment.

2. A stethoscope as defined in claim 1, wherein the respective sleeves have respective free end portions in 0pposed, spaced relation to said end portions of said arms and closely adjacent the respective webs to which said 3,288,246 3 4 sleeves are joined, whereby to provide substantially 360 I References Cited by the Examiner cirelimferential extent of engagement with said binaurals. UNITED STATES PATENTS 3. A stethoscope as defined in claim 1, wherein said sleeves are of axial length at least equal to their diameter, 693487 2/1902 BOY/16S 181 24 1,841,078 1/1932 Baird et al. 181--24 whereby they are of snfficient stiffness and bearing area 5 5 in engagement with said binaurals, to maintain appreci- 3/19 3 Rayder 181 24 able grasp on the binaurals when the latter are rotated in directions tending to drag the free ends of said sleeves RICHARD WILKINSON Primary Examiner in a direction to open the sleeves. STEPHEN J. TOMSKY, Examiner. 

1. A STETHOSCOPE COMPRISING A COMMUNICATION TUBE HAVING A PAIR OF FLEXIBLE BRANCH TUBES BRANCHING FROM ONE END THEREOF; A PAIR OF BINAURALS OF RIGID TUBING HAVING RESPECTIVE ENDS COUPLED TO RESPECTIVE ENDS OF SAID BRANCH TUBES; AND A YOKE OF SPRING SHEET MATERIAL HAVING RESPECTIVE ARMS OF SUBSTANTIALLY FLAT RIBBON FORM DISPOSED IN PLANES AT RIGHT ANGLES TO A COMMON PLANE OF SAID YOKE, HAVING THEIR ONE ENDS JOINED BY A TRANSVERSE CONNECTING BRIDGE AND HAVING, AT THEIR OTHER ENDS, INTEGRAL EXTENSIONS OF DIHEDRAL ANGULAR FORM COMPRISING RESPECTIVE END PORTIONS OF SAID ARMS AND RESPECTIVE WEBS JOINED TO SAID END PORTIONS BY RIGHT-ANGLE BENDS AND EXTENDING IN OPPOSITE DIRECTIONS IN A PLANE ADJACENT AND PARALLEL TO THE COMMON PLANE OF THE SIDE EDGES OF SAID ARMS AT ONE SIDE OF SAID YOKE, AND RESPECTIVE CURLED SLEEVES FORMED AS CONTINUATIONS OF SAID WEBS, TANGENT TO SAID WEBS, EXTENDING CONTINUOUSLY THEREFROM SUBSTANTIALLY ENTIRELY AROUND SAID BINAURALS, AND CENTERED IN THE GENERAL PLANE OF THE YOKE, SAID SLEEVES ENCIRCLING RESPECTIVE BINAURALS IMMEDIATELY ADJACENT THE ENDS OF SAID BRANCH TUBES WITH A YIELDING FRICTIONAL ENGAGEMENT SUCH AS TO PERMIT ROTATIONAL ADJUSTMENT OF SAID BINAURALS AND TO HOLD THEM IN SELECTED POSITIONS OF SUCH ROTATIONAL ADJUSTMENT. 